Normal and pathological eye tissues of the human and experimental animals have been studied by electron microscopy in order to elucidate pathogenesis of various eye diseases. Completed works during this fiscal year are: fine structure of the cornea, especially on the keratocyte; histopathological study on ocular changes induced by suckling mouse cataract agent; electron microscopic study of cataractous lenses of diabetic sand rats; electron microscopic and biochemical studies on experimentally induced Niemann-Pick disease-like changes in albino rats; degeneration of the pigmented ciliary epithelium by hyperosmotic shock to the monkey; fine structural studies on the conjunctiva of a case of Richner-Hanhart sundrome, and on the optic nerve and retina of a case of adrenoleukodystrophy; histologic and statistic study on metastatic skin melanoma to the eye; electon microscopic study of extraocular muscles in myotonic dystrophy. BIBLIOGRAPHIC REFERENCES: Sakuragawa, N., Sakuragawa, M., Kuwabara, T., Pentchev, P.G., Barranger, J.A. and Brady, R.O.: Niemann-Pick disease experimental model: Sphingomyelinase reduction induced by AY-9944. Science 196: 317-319, 1977. Kaiser-Kupfer, M., Kuwabara, T. and Kupfer, C.: Progressive bilateral essential iris atrophy. Am. J. Ophthalmol. 83: 340-346, 1977.